影响大跨悬索桥地震响应的敏感因素  

Sensitive Factors to Influence Seismic Response of Long-Span Suspension Bridge

作　　者：徐勋[1] 任伟平[1] 强士中[1] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031

出　　处：《华南理工大学学报（自然科学版）》2008年第11期108-113,120,共7页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(50278079);交通部西部交通建设科技项目(200431822317)

摘　　要：以四渡河悬索桥为研究对象,建立了该大跨钢桁架加劲梁悬索桥的空间动力计算模型,推导了基于Leger的大质量法(LMM)和基于拟静力位移概念的多支承激励下的非线性运动方程,在此基础上对该桥的地震反应进行了空间非线性时程分析,研究了土-桩-桥相互作用和中央扣设置方式对大跨悬索桥地震响应的影响.结果表明:土-桩-桥相互作用对悬索桥地震响应的影响与地震动输入方式密切相关,受水平地震波影响较大,而受竖向地震波的影响很小;一对柔性中央扣对加劲梁的纵桥向位移和应力响应均产生不利的影响,而刚性中央扣和3对柔性中央扣对限制加劲梁的纵桥向位移的作用显著,但是由此导致了结构地震应力响应的显著增加.In this paper, by taking the Sidu River Bridge as the example, a spatial dynamic model of long-span suspension bridges with steel truss stiffening girder is established, and the nonlinear motion equations in the multisupport excitation condition are deduced based on Leger＇s large-mass method （LMM） and the pseudo static displacement conception. Then, a 3D nonlinear time-history analysis of the seismic response of the bridge is performed, and the effects of soil-pile-bridge interaction and central buckle configuration on the seismic response are investigated. The results show that the effect of soil-pile-bridge interaction on the seismic response of suspension bridge is closely related to the excitation ways of seismic ground motion and is greatly affected by the horizontal component of seismic wave but slightly affected by the vertical component, that a pair of flexible central buckles has adverse effect on the longitudinal displacement and the stress response of stiffening girder, while a pair of rigid central buckles and three pairs of flexible central buckles significantly restrict the longitudinal displacement of stiffening girder although the seismic stress response of the structure greatly increases in this case.

关 键 词：大跨悬索桥 地震反应 影响因素 时程分析 中央扣 土-桩-桥相互作用 

分 类 号：U442.5[建筑科学—桥梁与隧道工程] TU311.3[交通运输工程—道路与铁道工程]